Air-conditioning apparatus and method

ABSTRACT

An air-conditioning apparatus includes upper and lower chambers, and first and second heat exchange units respectively disposed in the upper and lower chambers and respectively having first and second working fluids. The first heat exchange unit has a condenser and a first fan adapted to draw air into the upper chamber for exchange of heat with the condenser. The second heat exchange unit has an evaporator and a second fan adapted to draw air into the lower chamber for exchange of heat with the evaporator. First and second tubing units are respectively connected to the condenser and the evaporator and each has a heat exchange tube section. The heat exchange tube sections of the first and tubing units are associated with each other such that the second working fluid transfers heat to the first working fluid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Application No. 095141110, filed on Nov. 7, 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an air-conditioning apparatus and method.

2. Description of the Related Art

Referring to FIG. 1, a conventional air-conditioning system 1, such as an air-conditioner, a heater, or an air cooler/heater, includes a compressor 11, a condenser 12, a refrigerant controller 13, an evaporator 14, a tubing unit 15 interconnecting in series the compressor 11, the condenser 12, the refrigerant controller 13, and the evaporator 14 so as to form a closed circulating loop, and a fan 16. The compressor 11 compresses a low-pressure, low-temperature, vapor-state coolant into a high-pressure, high-temperature, vapor-state coolant. The condenser 12 condenses the high-pressure, high-temperature, vapor-state coolant into a high-pressure, medium-temperature, liquid-state coolant through a cooling medium such as air or water. The refrigerant controller 13 reduces the pressure of the high-pressure, medium-temperature, liquid-state coolant so as to form a low-pressure, medium-temperature, liquid-state coolant. The evaporator 14 vaporizes the low-pressure, medium-temperature, liquid-state coolant into a low-temperature, low-pressure, vapor-state coolant. The fan 16 directs a current of air toward the condenser 12 and the evaporator 14.

Through heat exchange of the evaporator 14 with the coolant and the current of air produced by the fan 16, the purpose of absorbing heat from a room to be cooled and the purpose of blowing cold air into the room are achieved. Simultaneously, through heat exchange of the condenser 12 with the coolant and the current of air produced by the fan 16, heat is dissipated into the outside air.

The conventional air-conditioning system 1 must rely on the compressor 11 to compress the coolant and the refrigerant controller 13 to reduce the pressure of the coolant so that the coolant can circulate smoothly and thereby effect heat absorption. Through use of such a configuration, however, the system 1 has many components, is costly, and is noisy. Furthermore, the system 1 also generates a significant amount of heat itself during the pressurization operation of the refrigerant controller 13, so that the efficiency of heat dissipation in the system 1 is low.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide an air-conditioning apparatus that has simple components, that can reduce noise to a minimum, and that can enhance the efficiency of heat dissipation. The present invention also provides an improved air-conditioning method.

According to one aspect of this invention, an air-conditioning apparatus comprises a housing, first and second heat exchange units, and first and second tubing units. The housing includes an upper chamber that has an upper air inlet and an upper air outlet, and a lower chamber that has a lower air inlet and a lower air outlet. The first heat exchange unit is disposed in the upper chamber, and has a first working fluid, a condenser to condense the first working fluid, and a first fan adapted to draw air into the upper chamber through the upper air inlet for exchange of heat with the condenser. The second heat exchange unit is disposed in the lower chamber, and has a second working fluid, an evaporator to vaporize the second working fluid, and a second fan adapted to draw air into the lower chamber through the lower air inlet for exchange of heat with the evaporator. The first tubing unit is connected to the condenser to form a closed circulating path that extends downward from and that extends upward to the condenser. The first working fluid circulates through the first tubing unit and the condenser. The first tubing unit has a heat exchange tube section disposed away from the condenser. The second tubing unit is connected to the evaporator to form a closed circulating path that extends downward to and that extends upward from the evaporator. The second working fluid circulates through the second tubing unit and the evaporator. The second tubing unit has a heat exchange tube section disposed away from the evaporator and associated with the heat exchange tube section of the first tubing unit such that the second working fluid transfers heat to the first working fluid.

According to another aspect of this invention, an air-conditioning method comprises the steps of: (a) circulating a first working fluid through a closed circulating path formed by a first tubing unit and a condenser to cause the first working fluid to flow upward and downward alternately; (b) circulating a second working fluid through a closed circulating path formed by a second tubing unit and an evaporator to cause the second working fluid to flow upward and downward alternately, the second tubing unit and the evaporator being disposed at a level generally below the first tubing unit and the condenser; (c) absorbing heat from air by evaporating the second working fluid in the evaporator so that the second working fluid flows upward; (d) liberating heat to air by condensing the first working fluid in the condenser so that the first working fluid flows downward; and (e) exchanging heat between the first and second working fluids at a level generally higher than the second tubing unit and generally lower than the first tubing unit so that the first working fluid evaporates and flows upward and the second working fluid condenses and flows downward.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:

FIG. 1 is a schematic view of a conventional air-conditioning system;

FIG. 2 is a schematic front view of the preferred embodiment of an air-conditioning apparatus according to the present invention;

FIG. 3 is a sectional side view of the preferred embodiment;

FIG. 4 is a fragmentary sectional view of a condenser/evaporator of the preferred embodiment; and

FIG. 5 is a flow chart, illustrating the steps involved in an air-conditioning method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2 to 4, the preferred embodiment of an air-conditioning apparatus according to the present invention is shown to comprise a housing 2, first and second heat exchange units 3, 4, and first and second tubing units 6, 7.

The housing 2 has an upper chamber 21, a lower chamber 22, an upper air inlet 23 and an upper air outlet 24 both formed in a front side of the housing 2 and both communicating with the upper chamber 21, and a lower air inlet 25 and a lower air outlet 26 both formed in a rear side of the housing 2 and both communicating with the lower chamber 22. The upper air inlet and outlet 23, 24 are communicated with a first temperature region, for example, an area outside of a room. The lower air inlet and outlet 25, 26 are communicated with a second temperature region, for example, an area inside of the room.

The first heat exchange unit 3 is disposed in the upper chamber 21, and has a condenser 31 proximate to the upper air outlet 24, and a first fan 32 disposed proximate to the condenser 31 opposite to the upper air outlet 24. The condenser 31 includes a vapor-receiving section 311 formed on a top end thereof, a liquid-receiving section 312 formed on a bottom end thereof, and a plurality of channels 313 connected between the vapor-receiving and liquid-receiving sections 311, 312. The first fan 32 is adapted to draw air from the first temperature region into the upper chamber 21 through the upper air inlet 23 for exchange of heat with the condenser 31.

The second heat exchange unit 4 is disposed in the lower chamber 22, and has an evaporator 41 proximate to the lower air outlet 26, and a second fan 42 disposed proximate to the evaporator 41 opposite to the lower air outlet 26. The evaporator 41 includes a vapor-receiving section 411 formed on a top end thereof, a liquid-receiving section 412 formed on a bottom end thereof, and a plurality of channels 413 connected between the vapor-receiving and liquid-receiving sections 411, 412. The second fan 42 is adapted to draw air from the second temperature region into the lower chamber 22 through the lower air inlet 25 for exchange of heat with the evaporator 41.

A thermoelectric cooler 5 is disposed between the upper and lower chambers 21, 22 of the housing 2 in an inclined manner with respect to a horizontal line, and has a hot side 53, and a cold side 54 opposite to the hot side 53 and having a cooling function. The thermoelectric cooler 5 is controlled through a circuit so as to keep the hot side 53 and the cold side 54 at constant hot and cold temperatures, respectively.

The first tubing unit 6 is connected to the condenser 31 to form a closed circulating path that extends downward from and that extends upward to the condenser 31. The first tubing unit 6 has a vapor-flowing tube section 62, a liquid-flowing tube section 63, and a heat exchange tube section 61 connected between the vapor-flowing and liquid-flowing tube sections 62, 63. The heat exchange tube section 61 is inclined with respect to the horizontal line so that the heat exchange tube section 61 has a lower end 611, and a higher end 612 opposite to and higher than the lower end 611. The heat exchange tube section 61 is in contact with the hot side 53 of the thermoelectric cooler 5, and is disposed away from the condenser 31. The vapor-flowing tube section 62 is connected to the vapor-receiving section 311 of the condenser 31 and the higher end 612 of the heat exchange tube section 61. The liquid-flowing tube section 63 is connected to the liquid-receiving section 312 of the condenser 31 and the lower end 611 of the heat exchange tube section 61.

The second tubing unit 7 is connected to the evaporator 41 to form a closed circulating path that extends downward to and that extends upward from the evaporator 41. The second tubing unit 7 has a vapor-flowing tube section 72, a liquid-flowing tube section 73, and a heat exchange tube section 71 connected between the vapor-flowing and liquid-flowing tube sections 72, 73. The heat exchange tube section 73 is inclined with respect to the horizontal line so that the heat exchange tube section 71 has a lower end 711, and a higher end 712 opposite to and higher than the lower end 711. The heat exchange tube section 71 is in contact with the cold side 54 of the thermoelectric cooler 5, and is disposed away from the evaporator 41. The vapor-flowing tube section 72 is connected to the vapor-receiving section 411 of the evaporator 41 and the higher end 712 of the heat exchange tube section 71. The liquid-flowing tube section 73 is connected to the liquid-receiving section 412 of the evaporator 41 and the lower end 711 of the heat exchange tube section 71. The second tubing unit 7 further has an insulating layer 74 that is made of a non-heat-conductive material and that covers the heat exchange tube section 71 and the liquid-flowing tube section 73.

The second tubing unit 7 and the evaporator 41 are disposed at a level generally lower than that of the first tubing unit 6 and the condenser 31. The thermoelectric cooler 5 is disposed at a level generally higher than the second tubing unit 7 and the evaporator 41 and generally lower than the first tubing unit 6 and the condenser 31.

First and second working fluids 30, 40 are respectively injected into the apparatus of the present invention after the first and second tubing units 6, 7, the condenser 31, and the evaporator 41 are evacuated, so that each of the first and second working fluids 30, 40 circulates in a vacuum environment. In this embodiment, the first and second working fluids 30, 40 are the same coolant that has a phase-change temperature of about 5-10° C. Alternatively, the first and second working fluids 30, 40 may be a super-thermal-conductive liquid.

Referring to FIG. 5, in combination with FIGS. 2 and 3, an air-conditioning method that can be carried out by the air-conditioning apparatus of the present invention includes the steps of evaporating the second working fluid 40, condensing the first working fluid 30, and exchanging heat between the first and second working fluids 30, 40. These steps will be described in greater detail below.

In step 81, the second working fluid 40 is circulated through the closed circulating path formed by the second tubing unit 7 and the evaporator 41 so as to flow upward and downward alternately. During such circulation, the second working fluid 40, which is in a liquid state, evaporates in the evaporator 41 and absorbs heat from air that is drawn into the lower chamber 22 through the lower air inlet 25 by the second fan 42. The air is thus cooled and is discharged through the lower air outlet 26. During evaporation, the vaporized second working fluid 40 flows upward along the channels 413 from the liquid-receiving section 412 and into the vapor-receiving section 411, after which the second working fluid 40 flows further upward to the heat exchange tube section 71 through the vapor-flowing tube section 72.

In step 82, the vaporized second working fluid 40, when reaching the heat exchange tube section 71, exchanges heat with the first working fluid 30 through the thermoelectric cooler 5. In particular, due to the cooling function of the cold side 54 of the thermoelectric cooler 5, the vaporized working fluid 40 in the heat exchange tube section 71 condenses and flows downward through the liquid-flowing tube section 73. The hot side 53 of the thermoelectric cooler 5 transfers heat from the second working fluid 40 to the heat exchange tube section 61 so that the first working fluid 30 evaporates in the heat exchange tube section 61 and flows upward through the vapor-flowing tube section 62.

In step 83, the first working fluid 30 is circulated through the closed circulating path formed by the first tubing unit 6 and the condenser 31 so as to flow upward and downward alternately. During circulation, the vaporized first working fluid 30, by condensing in the condenser 31, liberates heat to air which is drawn into the upper chamber 21 through the upper air inlet 23 by the first fan 32. The air becomes hot and is discharged out of the upper chamber 21 through the upper air outlet 24. During condensation, the condensed first working fluid 30 flows downward along the channels 313 by gravity from the vapor-receiving section 311 into the liquid-receiving section 312 from which the first working fluid 30 flows further downward to the heat exchange tube section 61 through the liquid-flowing tube section 63.

It should be noted that the insulating layer 74 of the second tubing unit 7 isolates the liquid-flowing tube section 73 from ambient temperature so that the liquid-state working fluid 40 in the liquid-flowing tube section 73 will not vaporize.

The advantages of the air-conditioning apparatus and method of the present invention can be summarized as follows:

Through phase change of the first and second working fluids 30, 40 from liquid to vapor and from vapor to liquid, through the downward flowing of the liquefied first and second working fluids 30, 40 by gravity, and through the flowing of the vaporized first and second working fluids 30, 40 by natural convection, the first and second working fluids 30, 40 can undergo self-circulation so that the compressor and the refrigerant controller, usually used in the conventional air-conditioning system 1 (see FIG. 1), are unneeded in the present invention. Therefore, the air-conditioning apparatus of the present invention is simple in construction, reduces cost and noise to a minimum, and minimizes self-generated heat.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. An air-conditioning apparatus, comprising: a housing including an upper chamber that has an upper air inlet and an upper air outlet, and a lower chamber that has a lower air inlet and a lower air outlet; a first heat exchange unit disposed in said upper chamber and having a first working fluid, a condenser to condense said first working fluid, and a first fan adapted to draw air into said upper chamber through said upper air inlet for exchange of heat with said condenser; a second heat exchange unit disposed in said lower chamber and having a second working fluid, an evaporator to vaporize said second working fluid, and a second fan adapted to draw air into said lower chamber through said lower air inlet for exchange of heat with said evaporator; a first tubing unit connected to said condenser to form a closed circulating path that extends downward from said condenser and that extends upward to said condenser, said first working fluid circulating through said first tubing unit and said condenser, said first tubing unit having a heat exchange tube section disposed away from said condenser; and a second tubing unit connected to said evaporator to form a closed circulating path that extends downward to said evaporator and that extends upward from said evaporator, said second working fluid circulating through said second tubing unit and said evaporator, said second tubing unit having a heat exchange tube section disposed away from said evaporator and associated with said heat exchange tube section of said first tubing unit such that said second working fluid transfers heat to said first working fluid.
 2. The air-conditioning apparatus of claim 1, further comprising a thermoelectric cooler that has a cold side and a hot side respectively in contact with said heat exchange tube sections of said second and first tubing units.
 3. The air-conditioning apparatus of claim 2, wherein all of said heat exchange tube sections of said second and first tubing units and said cold and hot sides of said thermoelectric cooler are inclined with respect to a horizontal line so that each of said heat exchange tube sections has a lower end, and a higher end opposite to and higher than said lower end.
 4. The air-conditioning apparatus of claim 3, wherein each of said condenser and said evaporator has a top end provided with a vapor-receiving section, a bottom end provided with a liquid-receiving section, and a plurality of channels connected between said vapor-receiving and liquid-receiving sections.
 5. The air-conditioning apparatus of claim 4, wherein said second tubing unit further has a vapor-flowing tube section connected to said vapor-receiving section of said evaporator and said higher end of said heat exchange tube section of said second tubing unit, and a liquid-flowing tube section connected to said liquid-receiving section of said evaporator and said lower end of said heat exchange tube section of said second tubing unit.
 6. The air-conditioning apparatus of claim 5, wherein said second tubing unit further has an insulating layer that is made of a non-heat-conductive material and that covers said heat exchange tube section and said liquid-flowing tube section of said second tubing unit.
 7. The air-conditioning apparatus of claim 1, wherein each of said first and second working fluids has a phase-change temperature of about 5-10° C.
 8. An air-conditioning method, comprising: (a) circulating a first working fluid through a closed circulating path formed by a first tubing unit and a condenser to cause the first working fluid to flow upward and downward alternately; (b) circulating a second working fluid through a closed circulating path formed by a second tubing unit and an evaporator to cause the second working fluid to flow upward and downward alternately, the second tubing unit and the evaporator being disposed at a level generally below the first tubing unit and the condenser; (c) absorbing heat from air by evaporating the second working fluid in the evaporator so that the second working fluid flows upward; (d) liberating heat to air by condensing the first working fluid in the condenser so that the first working fluid flows downward; and (e) exchanging heat between the first and second working fluids at a level generally higher than the second tubing unit and generally lower than the first tubing unit so that the first working fluid evaporates and flows upward and the second working fluid condenses and flows downward.
 9. The air-conditioning method of claim 8, wherein each of said first and second working fluids has a phase-change temperature of about 5-10° C. 